Preliminary steps for fabrication of microfluidic systems for swine sperm sorting: Materials, perfusing systems and flow.

The success rate of assisted reproductive techniques in the livestock production can be optimized by improving the quality of the semen sample by selecting only the good quality sperm from the ejaculate. Microfluidic technology has been studied for sperm sorting mainly in human ejaculates but has not been studied for boar sperm. Spermatozoa have been proven to be highly sensitive to different microplastics, but the potential toxic effects of the materials used to set up microfluidic systems have not been studied. The main goal of this study was to assess the possible toxic effect on boar sperm of materials commonly used for a microfluidic system and to evaluate the effect of different flow control systems (peristaltic pump, syringe pump and a microfluidic flow controller) at different flow rates (10 μl*min-1, 100 μl*min-1 and 1 ml*min-1) on sperm quality, as preliminary information for the development of a swine sperm sorting microfluidic system. Results showed no negative effect of the different materials at different concentrations. The control reached the highest curvilinear velocity compared to the peristaltic pump and the pressure-based flow control system. In the flow rates, 10 μm*min-1 showed the poorest results and no significant differences were observed between control and 1 mlmin-1 flow in any of the parameters. In conclusion, all materials that were studied for microfluidic fabrications were suitable for sperm sorting, any of the pumps would be suitable for sperm selection and 1 ml*min-1 flow rate would be the flow rate of choice for sperm pumping.